Google Arrests Apple's Development

Tech investors should take a page from the geeks and pay close attention to developer conferences. Watching Google's, it is easier to understand the great rotation into the search giant's stock.

Six months ago, Apple had a market value of about $550 billion; Google, around $230 billion. Since then, as Google shares have risen by a third and Apple's have dropped by a quarter, the gap has shrunk to about $100 billion. Before long, Google may end up as the most valuable tech company. Adjusting for cash, the companies are already...